Hearing aid



FIG. 1 is a bottom and rear perspective view of a hearing aid, with the environmental elements in broken lines;

FIG. 2 is a top and front perspective view thereof;

FIG. 3 is another bottom and rear perspective view thereof, with the environmental elements removed for clarity;

FIG. 4 is a rear perspective view thereof;

FIG. 5 is a bottom perspective view thereof;

FIG. 6 is a front perspective view thereof;

FIG. 7 is a top perspective view thereof;

FIG. 8 is a side view thereof; and,

FIG. 9 is another side view thereof.

The broken lines in FIGS. 1 and 2 represent the environment, and the broken lines in FIG. 4 are included for the purpose of illustrating a portion of the hearing aid that forms no part of the claimed design. None of the broken lines form part of the claimed design. 

The ornamental design for a hearing aid, as shown and described. 